Apparatus for forming foundation columns



Aug. 3, 1937. E. A. SMITH APPARATUS FOR FORMING FOUNDATION COLUMNS Filed Feb. 27. 1935 5 Sheets-Sheet l FIG...

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Aug. 3, 1937. I E. A. SMITH 2,039,041

APPARATUS FOR FORMING FOUNDATION COLUMNS Filed Fb. 27, 1935 5 Sheets-Sheets 34 FIGZ 11%VENT0R.

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Patented Aug. 3, 1937 I 2,0sac41 PATENT OFF! 2,089,041 "APPARATUS FO FORMING FOUNDATION COLUMNS E cilvva -d SmithChatham, N. 3., assignor to Caisson Contracting Company, New York, N. Y

a corporation of Delaware Application February 27, 1935, SerialNo. 8,493

' i Claims.

This invention pertains to theiorming of foundation columns for supporting superstructures, and is an improvement in the methods andapparatus disclosed in Patent No. 1,654,600, issued 5 January 3, 19 28, to'Po-well, Patent No. 1,904,079 issued April 18, 1933, to Powell, and Patent 'No. 1,931,845 issued October 24, 1933, to Hart and Schroeder.

In the Hart and Schroeder patent thecutting is done by a steel casing having a rotatable annular cutter at its lower end, with fluid (usually water) fed to the cutter. If the'specifications of' the job require that the hole be lined with steel, the casing and cutter are left in the hole to form the lining.

The Hart and Schroeder patent contemplates using suificient water to wash'awaythe detritus produced by the cutter, but I have found in practice" that by properly controlling 'the supply of water, in the presence of 'suitable material, 'the mud effect of Powell Patent No. 1,654,600'may be produced around the cutter "barrel. I have also found that in the practice of the Hart and Schroeder invention, 'rotationof the water Within 5 the casing and cutter usually serves tobreak "down thecore as it is formed. These facts make it possible to rotate a cutter of much greater length than the relatively short cutter shown in the Hart and Schroeder patent, because the mud lubricates the exterior of the casing and prevents caving of the walls of the hole, while the destruction of the core greatly reduces friction inside the casing. In some cases the barrel of the cutter may be as long as the finished hole. This has made possible the improvements in practice disclosed herein.

Some of the advantages of the present invention are:-

Better results are obtained at lower cost.

All joints may be made tight and of full strength by welding or bolting above ground.

A straight hole can always be produced because cutter and casing are rigidly connected in fixed alignment.

The drilling and lining of the hole may be done in a single operation.

The drive head is usually on the top of the casing, above ground, and therefore under observation and accessible.

Boulders or thick layers of hardpan may be cut at any stageof the drilling operation without interference by the drive head.

1 No grouting operation is necessary to close the joint between the two sections of the cutter, as in 55 Hart and Schroeder.

It is possible at any stage of the drilling operation to remjove the drive head-and either pump out the casing or attach an airlock to the top of the casing and send a man down to make an inspection or remove an obstruction, without having to caulk the joint between casing and cutter to prevent water or air leakage.

In the Hart and Schroeder method the casing and cutter must sometimes be supported independently of each other. All necessity for dual 10 support is avoided in the present construction.

If a-column with an enlarged base be desired, or if the lining is to be drawn from the hole during "or'after concreting, the shaft used above the cutter during the drilling operation may be of reduced diameter, the cutter corresponding to the working chamber of Patent 1,904,079 and the upwardly extending shaft being required only to satisfy the design and to provide space for the passage of a man-and conduits for fluid, thereby 0 reducing cost, especially since a reduced-diameter drill shaft "may be-used with cutters of various diameters simply by providing suitable adapters. Furthermore, the present process avoids the use of airlocks as in Powell 1,904,079.

Further and other objects and advantages will be apparent from the specification and claims, andffom the accompanying drawings which illustra'te "what is now considered the preferred embodiment of the invention.

In the drawings:

Fig. 1 shows the apparatus in operation.

Fig. 2 is a plan view of Fig. 3.

Fig.3 is a cross-section on line 33 of Fig. 2, showing the casing sunk to rock and filled with concrete.

Fig. 4 is an enlarged cross-section of casing, showing drive stem, drive head, water conduits, pressure control valve, etc.

Fig. 5 is a cross-section on line 5-5 of Fig. 4.

' Fig. 6 is a detail cross-section on line 6-6 of Fig. 4,

Fig. 7 shows a completed column having a reduced-diameter shaft.

Fig. 8 shows a full-diameter column being concreted while the cutter with reduced-diameter shaft is being withdrawn.

Fig. 9 shows the column of Fig. 8 completed.

Fig. 1 shows the casing 20 sinking to rock 22, being rotated by gears 24, 26, through the instrumentality of drill stem 28 and conical drive head 30, attached at its top to the drill stem and at its bottom to the casing. The lower end of the casing is provided with means for cutting into the ground and rock. As illustrated in the drawings the cutting means is the type of annular core cutter shown in the Hart and Schroeder patent, comprising a double wall barrel providing between the walls an annular space 32 through 5 which water and shot may be supplied to the cutting edge. If the cutting edge be furnished with teeth or other abrasives neither the shot nor the double wall cutter may be necessary.

Water is supplied through hose 34, swivel 36,

hollow drill stem 28, and conduits 38 to space 32 through which the water passes to the cutting edge. Valve 40 in hose 34 is available to control the rate of flow.

Flow of water from the cutter into the interior of the casing may be controlled by valve 42 in head 30. If valve 42 be kept closed the entire casing will act like a diving bell and the water will rise only slightly in the casing, depending on the static head outside the casing. It is usually advisable, however, to open valve 42 enough to admit water into the casing, because the water and any loose material, rotating with the casing, serves to break down the core 44 formed in the casing. Usually most of the water fed to the cutter passes upwardly in space 46 between the outside of the casing and the wall of the hole, the rate of flow being controlled by valves 40 and 42. Mud formed in space 46 tends to prevent collapse of the wall against the casing, and serves to lubricate the casing.

Conduits 38, as illustrated, comprise steel channels welded to the inner wall of the casing and E to the core barrel as will be readily apparent from the drawings. Casing is usually made up of comparatively short sections welded together, but if a bolted joint be desired it may be made with angles 48, 50 and packing 52 (Figs. 4 and 5), conduit 38 passing through the angles as in Fig. 6. p 40 When the bottom of the casing is properly seated in rock, head 30 is removed, the casing is pumped out, inspected, and filled with concrete 54 as in Fig. 3 to form the finished column.

If a column with an enlarged base be desired, 45 or if the casing is to be withdrawn during concreting, the apparatus of Figs. 7 and 8 may be used. This is similar to the disclosure of Powell Patent No. 1,904,079, except that here the bottom of the bell is provided with cutting means, water is fed to the cutter through conduits as in 1-6 and the casing (comprising bell 56 and shaft 58) is rotated as in Fig. 1 to sink it into the ground. The shaft need only be large enough to permit passage of a man and to provide space for the conduits. No air lock is necessary.

After the casing reaches proper footing, it may may be pumped out and filled with concrete 60 to form a column with enlarged base (Fig. 7), or it may be withdrawn as the concreting proceeds (Fig. 8) to form a concrete column 62 the full diameter of the hole (Fig. 9).

It is to be understood that the invention is not limited to the specific embodiment herein illustrated and described but may be used in other ways without departure from its spirit as defined by the following claims.

1. Apparatus for forming a foundation column in the ground, comprising in combination, an annular casing closed at its upper end and open at its lower end, means for rotating said casing while it is upright in the ground, cutting means on the bottom of said casing, means for feeding water to said cutting means, and means under control of the operator for regulating the relative flows of water to the exterior and interior of said casing.

2. Apparatus for forming a foundation column in the ground, comprising in combination, an annular casing closed at its upper end and open at its lower end, means for rotating said casing while it is upright in ground containing water, cutting means on the bottom of said casing, and means under control of the operator for regulating flow of water into said casing.

3. Apparatus for forming a foundation column in ground containing water, comprising in combination, an annular bell-shaped casing, means for rotating said casing whereby'its open end cuts intothe ground, and means for controlling flow of water into said casing.

4. The invention set forth in claim 3 in which said casing is air-tight and in which said controlling means comprises a manually operable vent valve in said casing. I

5. The invention set forth in claim 2 in which the regulating means comprises a manually operable vent valve, in said casing.

' EDWARD A. SMITH. 

